WASHINGTON (AP) -- Lawyers hired by the federal mortgage giant Freddie Mac are quietly looking into the firm's own lobbying campaign, an effort that helped snuff out proposed new regulations before the housing market collapsed. Freddie Mac was placed under direct government control because of its massive investment losses. The inquiry follows stories by The Associated Press that some two million dollars were paid to a Washington lobby group which then targeted 17 Republican senators to defeat a 2005 bill that would have required the firm to sell its then-lucrative mortgage portfolios. Months later, their value had plummeted. Also under review: six-figure payments to more than 50 outside lobbying firms and political consultants, including firms connected to former Senator Al D'Amato and former Speaker of the House Newt Gingrich. And, the use of a Washington skybox seat belonging to the lobby group by a Freddie Mac executive.